1. Field of the Invention
The present invention relates to a substrate, an optical writing device, and an image forming apparatus.
2. Description of the Related Art
Conventionally, a light-emitting element, such a laser diode, having a plurality of pin-like terminals is mounted on a substrate by inserting the pin-like terminals into holes provided in the substrate and soldering the terminals to the substrate. In this case, a large number of the terminals of the laser diode make it difficult to insert the terminals into the holes of the substrate, and whereby only slight bending of the terminals may make it impossible to insert the terminals.
Japanese Patent No. 2638953 discloses a technique in which a printed substrate is constituted by a flexible printed substrate backed with a reinforcing plate, and either a hole portion of the flexible substrate is made smaller than a hole portion of the reinforcing plate, or holes of the flexible substrate are connected by slits, thus making it possible to automatically insert terminals of a semiconductor laser into the printed substrate.
However, Japanese Patent No. 2638953 does not disclose mounting of a plurality of light-emitting elements closely. In case of mounting a plurality of light-emitting elements on the substrate closely, the terminals of each light-emitting elements are disposed densely. It leads degradation and difficulty of soldering of the terminals. Therefore, there is a need for providing a substrate, an optical writing device, and an image forming apparatus that can make it easy to solder the terminals of a plurality of light-emitting elements when the light-emitting elements are closely mounted.